Direct Stereoselective Synthesis of 2-Deoxyglycosides via Visible-Light-Induced Photoacid-Catalyzed Activation of Glycosyl o-[1-(p-MeO-Phenyl)vinyl]benzoates (PMPVBs) as Donors

Abstract

The photoacid-catalyzed synthesis of 2-deoxy glycosides is presented using stable glycosyl o-[1-(p-MeO-Phenyl)vinyl]benzoate (PMPVB) donors and employing the eosin Y and diphenyl disulfide (PhSSPh) catalytic system in the presence of blue LED lights. The remote activation of the alkene functionality under the photoacid catalysis followed by a 5-exo-trig cyclization led to the generation of oxocarbenium ions that were trapped to provide the glycosylated products in excellent yields and decent selectivities under mild conditions. This method is also useful for the photoacid-catalyzed synthesis of p-methoxybenzyl-alkyl ethers.